Pattern device for foundry molds

ABSTRACT

Disclosed is a device for replacing patterns for molds disposed on a replaceable pattern supporting unit. The pattern unit is centered by a centering frame and supported on a lifting member. The lifting member is connectable to the bottom of the pattern supporting unit by a turnable locking flange biased downwardly by a spring or hydraulically. At the lowered position of the unit, the flange locks this unit to the pattern table and during the lift of the unit the flange becomes released.

United States Patent 11 1 Buhrer et al.

[4 1 May 1, 1973 1 PATTERN DEVICE FOR FOUNDRY MOLDS [75] lnventors: Erwin Buhrer, Vogelingasschen 40,

' Schaffhausen; Franz Keller, Neuhausen am Rheinfall, both of Switzerland [73] Assignee: said Buhrer, by said Keller 22 Filed: Apr. 27, 1971 [21] App1.No.: 137,828

[30] Foreign Application Priority Data May 15, 1970 Switzerland ..7332/70 [52] US. Cl. ..164/24l, 164/137, 164/341 [51] Int. Cl ..B22c 7/04 [58] Field of Search 164/37, 40, 137, 164/207, 210, 211, 212, 239, 240, 241, 242, 243, 341

[56] References Cited UNlTED STATES PATENTS 3,568,754 3/1971 Geiger ..l64/24l X 2,894,299 7/ 1959 Buhrer 164/239 FOREIGN PATENTS OR APPLICATIONS,

1,159,135 12/1963 Germany ..l64/241 158,400 10/1963 U.S.S.R. ..164/241 Primary EXaminerJ. Spencer Overholser Assistant Examinerw-lohn E. Roethel 5 7 ABSTRACT Disclosed is a device for replacing patterns for molds disposed on a replaceable pattern supporting unitflhe pattern unit is centered by a centering frame and supported on a lifting member. The lifting member is connectable to the bottom of the pattern supporting unit by a turnable locking flange biased downwardly by a spring or hydraulically. At the lowered position of the unit, the flange locks this unit to the pattern tableand during the lift of the unit the flange becomes released.

4 Claims, 4 Drawing Figures Patented May 1, 1973 4 Sheets-Sheet 5 INVENTOR S E8 wm/ I3 j/14mg Patented May 11, 197.3 3,730,253

4 Sheets-Sheet 4 3 u H. A?

INVI I NTOR 5. E)! WIN [3 UHREA BY 1:- FAWMA K a 4 Them rim/e415 PATTERN DEVICE FOR FOUNDRY MOLDS BACKGROUND OF THE INVENTION This invention relates generally to foundry molds and, more particularly, to a pattern device for replacing pattern supporting units from a centering frame and affixing those units to a pattern-table.

In pattern devices for foundry molds having frame means for centering the pattern plates or partial pattern plates, it is advantageous to affix directly or indirectly, those pattern plates to a mold table. Since the molds may differ considerably as to their sizes, the possibility of. assembling a plurality of the partial pattern plates into a single pattern unit is more and more required. It is, therefore, necessary to enable the replacement of partial pattern plates assembled in a single pattern unit which can bethus accomodated for different castings. By increasing the size of a mold, the weight increases proportionally and the pattern units can no longer be replaced manually but mechanical devices mustbe employed. I

The hitherto known mechanical devices of this kind enable the seizure of the pattern plates from their upper surface only. In practical operation, however, such limitation brings about difficulties.

Another disadvantage of prior art pattern devices lies in the necessity to employ screw connections between the pattern plates and the pattern table. The screw connection impedes the replacement and, if used in a jarram molding machine, they may become loosened.

It is, therefore, an object of this invention to provide a pattern device which enables a lateral seizing of pat tern plates.

Another object of this invention is to insure a fast and reliable fixing of the assembled pattern plates to the pattern table.

SUMMARY OF THE INVENTION According to this invention, the above objects are attained by providing a lifting device which lifts one or more pattern plates together with associated heating plates and base plates at a distance above the'frame so that all these plates can be laterally seized for replacement. Besides, the lifting device is designed for lowering the assembled pattern plates and placing them on the pattern table to which they become affixed directly or indirectly.

BRIEF DESCRIPTION OF THE DRAWING For a better understanding of the invention, reference may be made to the following detailed description of two exemplary embodiments, taken in conjunction with the accompanying drawing, in which:

FIG. I is a fragmentary elevation view, partly in section, of a pattern device having a replaceable unit in its released and lifted position;

FIG. 2 is a sectional elevation view of the pattern device of this invention with a tightly locked replaceable unit;

FIG. 3 is a sectional plan view taken along line lI-II of FIG. 2; and

FIG. 4 is a sectional elevation view of a pattern device having a replaceable unit clamped by another embodiment of a lifting device.

2 DETAILED DESCRIPTION FIGS. 13 show a frame 1 affixed to a pattern table 14 and supporting a laterally arranged centering device 5'. A replaceable pattern supporting unit, consisting of a subframe 4 and pattern plates 2, is removably seated within the frame 1. The pattern plates 2 are secured to the top of subframe 4 by screws 81 and support on their top surface patterns 3. The lateral top edge of subframe 4 is provided with grooves 7 for seizing the entire pattern supporting unit and effecting; its replacement. The bottom of the subframe 4 has a stepped recess 9 in which a longitudinal locking flange l0, integral with a lifting truing-up trunnion 6, is disposed.

FIG. 1 illustrates the truing-up trunnion 6 and thus the entire pattern supporting unit in an elevated position whereby the longitudinal locking flange 10 is disengaged with the stepped recess 9. The centering device 5 is also in its unactuated position so that the pattern unit 4,2 is ready for being replaced.

FIG. 2 illustrates in more detail the pattern supporting unit 2,4, frame 1, pattern table 14, and an unactuated mechanical liftingmember 18. The pattern table 14 is provided with a bore 17 having a top shoulder 11 in which the truing-up. trunnion 6 is guided for a vertical movement. A tension helical spring 13 acts against a tightening ring 16 which is secured to the trunnion 6 within the bore 17 and urges the locking flange 10 downwardly. In the low position, the locking flange 10 is turned into engagement with the stepped recess 9 at the bottom of the frame 1 and'the entire pattern unit 4,2 is thus firmly attached to the top surface of the pattern table 14. The centering device 5 has before clamped and centered the subframe 4 from its sides. The wall of the bore 17 is providledwith a helical slot 12 (shown in dashed lines) which leads upwards about a distance 20 and extends degrees about the periphery of the trunnion 6. A guiding pin 15 which is integral with the truing-up trunnion 6, is in engagement with the helical slot 12 and causes the rotary movement of the trunnion 6 together with the locking flange 10 about 90 when the lifting member 18 moves through its plunger rod 19 the trunnion 6 upwardly to the final unlocked position of the flange 10, as seen in FIG. 1.

The arrangement of the longitudinal locking'flange 10 in the stepped recess 9 in the bottom portion of the subframe 4 is shown in FIG. 3. The recess9 is provided at two opposite sides thereof with. locking steps against which the ends of the locking flange 10 abut. If the trunnion 6 is turned about 90 to an unlocked position of the flange l0 (dash and dot lines), the latter can pass freely through the opening between these locking steps.

FIG. 4 shows a modification of the liftingdevice for the pattern unit of FIG. 1. Instead of a mechanical lifting member and a tension spring, a hydraulical lifting plunger 21 is movably arranged in a hermetically sealed cylinder 28, and controlled by pressure conduits 26 and 27. A truing-up trunnion 6 has a projecting guiding pin 24 which is guided in a helical slot in the wall of a bore in the pattern table 14, similarly as in FIG. 2.

The number of lifting members 18 or 28 corresponds usually to the number of pattern supporting units which can be also equipped with heating plates and/or base plates (not shown).

The operation of the embodiment as shown in FIGS. 1 to 3 is as follows: A pattern machine comprises a plurality of lifting members 18 which are arranged in alignment with the axes of truing-up trunnions 6 in the pattern table 14. To replace the pattern supporting units 2,4, the centering device 5 is first released and, subsequently, the lifting member 18 is actuated. The plunger rod 19 starts forcing the trunnion 6 upwards and, due to the positive engagement of the guiding pin 15 in the helical slot 12, the longitudinal flange 10 is turned about 90 during the lift 20 and disengaged from the stepped recess 9. In the lifted, unlocked position, the upper part of the pattern unit projects above the rim of the frame 1 and can be laterally seized by the holding grooves 7 and replaced for another pattern unit. Prior to the replacement of a new unit, the lifting members 18 must be, therefore, in their elevated positions. The downward movement of the pattern unit and its affixing to the pattern table 14 is initiated by the reversed actuation of the lifting member 18. Due to the effect of the tension spring 17, the trunnion 6 is turned during the descending movement about 90 and, consequently, the angularly displaced flange l abuts by its ends against the steps 90 in the recess 9, and the entire force of the spring 17 now firmly fastens the pattern unit 4,2 on the pattern table 14, thus securing the unit against vibrations. Simultaneously, the centering device adjusts a desired lateral position of the pattern unit on the table 14 and within the frame 1.

The operation of the embodiment of FIG. 4 differs from the previous one in that during the lifting action of the hydraulical cylinder 28 and plunger 21, the pressure fluid is introduced through the bottom conduit 26 and discharged from the top conduit 27. During the lowering of the plunger 21, the flow is reversed and the top conduit 27 remains under pressure and the flange 23 firmly retains the subframe 4 to the pattern table 14.

be limited to the exact details of construction shown and described, for obvious modifications will occur to.a person skilled in the art.

Having thus described the invention, what we claim as new and desire to be secured by Letters Patent, is as follows:

l. A pattern device for foundry molds comprising a replaceable pattern supporting unit, a pattern table, a centering frame for said pattern supporting unit, and lifting means for vertically displacing said replaceable pattern supporting unit in said frame, said lifting means further comprising locking means operable for arresting at its low position said pattern supporting unit on said pattern table and, respectively, for releasing said unit at its elevated position.

2. A pattern device according to claim 1, wherein said locking means comprising a stepped recess in the bottom of said replaceable pattern supporting unit, a iongitudinal flange disposed within said recess and fixedly connected to a vertical truing-up trunnion suported for a rotary and a vertical movement in said pat- .ern table, and means for turning said flange via said trunnion about during the upward movement of said lift means.

3. A pattern device according to claim 2, wherein said trunnion is biased downwardly to a locked position of said flange by a helical tension spring.

4. A pattern device according'to claim 2, wherein said trunnion is connected to and controlled by a hydraulic lifting means.

t i t 1 i 

1. A pattern device for foundry molds comprising a replaceable pattern supporting unit, a pattern table, a centering frame for said pattern supporting unit, and lifting means for vertically displacing said replaceable pattern supporting unit in said frame, said lifting means further comprising locking means operable for arresting at its low position said pattern supporting unit on said pattern table and, respectively, for releasing said unit at its elevated position.
 2. A pattern device according to claim 1, wherein said locking means comprising a stepped recess in the bottom of said replaceable pattern supporting unit, a longitudinal flange disposed within said recess and fixedly connected to a vertical truing-up trunnion supported for a rotary and a vertical movement in said pattern table, and means for turning said flange via said trunnion about 90* during the upward movement of said lift means.
 3. A pattern device according to claim 2, wherein said trunnion is biased downwardly to a locked position of said flange by a helical tension spring.
 4. A pattern device according to claim 2, wherein said trunnion is connected to and controlled by a hydraulic lifting means. 